How to get the Structuremap IContainer instance from Asp.Net MVC 5 Dependency Resolver

Question

I am using Structuremap as my Dependency Resolver. I am trying to implement Container Per Request Pattern on my Global.asax.cs file.

    public IContainer Container
    {
        get
        {
            return (IContainer)HttpContext.Current.Items["_Container"];
        }
        set
        {
            HttpContext.Current.Items["_Container"] = value;
        }
    }


   public void Application_BeginRequest()
   {
       Container = ObjectFactory.Container.GetNestedContainer();
   }

As the ObjectFactory will not be supported in the future versions of Structuremap I would like get access to the container from the DependencyResolver. How is possible?

Thanks in Advance.

Noufal

Answer 1

Having ran into this question myself, this was the best guide I could find for registering StructureMap with ASP.NET MVC's Dependency Resolver (via the CommonServiceLocator package ).

I've copied and pasted the aforementioned article's solution, but I would recommend going through the benefits of this solution in the original article.

public class StructureMapDependencyResolver : ServiceLocatorImplBase
{
    private const string StructuremapNestedContainerKey = "Structuremap.Nested.Container";
    public IContainer Container { get; set; }

    private HttpContextBase HttpContext
    {
        get
        {
            var ctx = Container.TryGetInstance<HttpContextBase>();
            return ctx ?? new HttpContextWrapper(System.Web.HttpContext.Current);
        }
    }

    public IContainer CurrentNestedContainer
    {
        get { return (IContainer)HttpContext.Items[StructuremapNestedContainerKey]; }
        set { HttpContext.Items[StructuremapNestedContainerKey] = value; }
    }

    public StructureMapDependencyResolver(IContainer container)
    {
        Container = container;
    }

    protected override IEnumerable<object> DoGetAllInstances(Type serviceType)
    {
        return (CurrentNestedContainer ?? Container).GetAllInstances(serviceType).Cast<object>();
    }

    protected override object DoGetInstance(Type serviceType, string key)
    {
        var container = (CurrentNestedContainer ?? Container);

        if (string.IsNullOrEmpty(key))
        {
            return serviceType.IsAbstract || serviceType.IsInterface
                       ? container.TryGetInstance(serviceType)
                       : container.GetInstance(serviceType);
        }

        return container.GetInstance(serviceType, key);
    }

    public void Dispose()
    {
        if (CurrentNestedContainer != null)
        {
            CurrentNestedContainer.Dispose();
        }

        Container.Dispose();
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return DoGetAllInstances(serviceType);
    }

    public void DisposeNestedContainer()
    {
        if (CurrentNestedContainer != null)
            CurrentNestedContainer.Dispose();
    }

    public void CreateNestedContainer()
    {
        if (CurrentNestedContainer != null) return;
        CurrentNestedContainer = Container.GetNestedContainer();
    }
}

You can then set the resolver like so:

public class MvcApplication : System.Web.HttpApplication
{
    public static StructureMapDependencyResolver StructureMapResolver { get; set; }

    protected void Application_Start()
    {
        ...

        // Setup your Container before 
        var container = IoC.Initialize();
        StructureMapResolver = new StructureMapDependencyResolver(container);
        DependencyResolver.SetResolver(StructureMapResolver);
    }

    protected void Application_BeginRequest(object sender, EventArgs e)
    {
        StructureMapResolver.CreateNestedContainer();
    }

    protected void Application_EndRequest(object sender, EventArgs e)
    {
        StructureMapResolver.DisposeNestedContainer();
    }    
}

The great result of this type of configuration is you receive a new child container per request, with the container being disposed of at the end of each request.

Answer 2

我只是尝试过此方法及其工作方式，如果不是最佳方法，请让我使用。

StructuremapMvc.StructureMapDependencyScope.Container

Answer 3

There are two dependency resolvers one for ASP.NET MVC and other for ASP.NET Web Api

Web Api: Use WebApiContrib.IoC.StructureMap.StructureMapResolver

MVC: Use StructureMapDependencyResolver

public class StructureMapDependencyResolver : StructureMapDependencyScope, IDependencyResolver
{
    public StructureMapDependencyResolver(IContainer container)
        : base(container)
    {
    }

    public IDependencyScope BeginScope()
    {
        var child = Container.GetNestedContainer();
        return new StructureMapDependencyResolver(child);
    }
}

public class StructureMapDependencyScope : ServiceLocatorImplBase, IDependencyScope
{
    protected readonly IContainer Container;

    public StructureMapDependencyScope(IContainer container)
    {
        if (container == null)
        {
            throw new ArgumentNullException(nameof(container));
        }
        Container = container;
    }

    public void Dispose()
    {
        Container.Dispose();
    }

    public override object GetService(Type serviceType)
    {
        if (serviceType == null)
        {
            return null;
        }
        return serviceType.IsAbstract || serviceType.IsInterface
            ? Container.TryGetInstance(serviceType)
            : Container.GetInstance(serviceType);
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return Container.GetAllInstances(serviceType).Cast<object>();
    }

    protected override IEnumerable<object> DoGetAllInstances(Type serviceType)
    {
        return Container.GetAllInstances(serviceType).Cast<object>();
    }

    protected override object DoGetInstance(Type serviceType, string key)
    {
        if (string.IsNullOrEmpty(key))
        {
            return serviceType.IsAbstract || serviceType.IsInterface
                ? Container.TryGetInstance(serviceType)
                : Container.GetInstance(serviceType);
        }
        return Container.GetInstance(serviceType, key);
    }
}

Usage is as follows...

public static class Ioc
{
    public static void Config()
    {
        var container = InitializeContainer();

        var webApiDependencyResolver = new StructureMapResolver(container);
        GlobalConfiguration.Configuration.DependencyResolver = webApiDependencyResolver;

        var mvcDependencyResolver = new StructureMapDependencyResolver(container);
        DependencyResolver.SetResolver(mvcDependencyResolver);
    }
}

public class WebApiApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        Ioc.Config();
        ...
    }
}